diff options
Diffstat (limited to 'drivers/input/misc/kxtj9.c')
| -rw-r--r-- | drivers/input/misc/kxtj9.c | 550 |
1 files changed, 550 insertions, 0 deletions
diff --git a/drivers/input/misc/kxtj9.c b/drivers/input/misc/kxtj9.c new file mode 100644 index 000000000..52313c6e3 --- /dev/null +++ b/drivers/input/misc/kxtj9.c @@ -0,0 +1,550 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2011 Kionix, Inc. + * Written by Chris Hudson <chudson@kionix.com> + */ + +#include <linux/delay.h> +#include <linux/i2c.h> +#include <linux/input.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/input/kxtj9.h> + +#define NAME "kxtj9" +#define G_MAX 8000 +/* OUTPUT REGISTERS */ +#define XOUT_L 0x06 +#define WHO_AM_I 0x0F +/* CONTROL REGISTERS */ +#define INT_REL 0x1A +#define CTRL_REG1 0x1B +#define INT_CTRL1 0x1E +#define DATA_CTRL 0x21 +/* CONTROL REGISTER 1 BITS */ +#define PC1_OFF 0x7F +#define PC1_ON (1 << 7) +/* Data ready funtion enable bit: set during probe if using irq mode */ +#define DRDYE (1 << 5) +/* DATA CONTROL REGISTER BITS */ +#define ODR12_5F 0 +#define ODR25F 1 +#define ODR50F 2 +#define ODR100F 3 +#define ODR200F 4 +#define ODR400F 5 +#define ODR800F 6 +/* INTERRUPT CONTROL REGISTER 1 BITS */ +/* Set these during probe if using irq mode */ +#define KXTJ9_IEL (1 << 3) +#define KXTJ9_IEA (1 << 4) +#define KXTJ9_IEN (1 << 5) +/* INPUT_ABS CONSTANTS */ +#define FUZZ 3 +#define FLAT 3 +/* RESUME STATE INDICES */ +#define RES_DATA_CTRL 0 +#define RES_CTRL_REG1 1 +#define RES_INT_CTRL1 2 +#define RESUME_ENTRIES 3 + +/* + * The following table lists the maximum appropriate poll interval for each + * available output data rate. + */ +static const struct { + unsigned int cutoff; + u8 mask; +} kxtj9_odr_table[] = { + { 3, ODR800F }, + { 5, ODR400F }, + { 10, ODR200F }, + { 20, ODR100F }, + { 40, ODR50F }, + { 80, ODR25F }, + { 0, ODR12_5F}, +}; + +struct kxtj9_data { + struct i2c_client *client; + struct kxtj9_platform_data pdata; + struct input_dev *input_dev; + unsigned int last_poll_interval; + u8 shift; + u8 ctrl_reg1; + u8 data_ctrl; + u8 int_ctrl; +}; + +static int kxtj9_i2c_read(struct kxtj9_data *tj9, u8 addr, u8 *data, int len) +{ + struct i2c_msg msgs[] = { + { + .addr = tj9->client->addr, + .flags = tj9->client->flags, + .len = 1, + .buf = &addr, + }, + { + .addr = tj9->client->addr, + .flags = tj9->client->flags | I2C_M_RD, + .len = len, + .buf = data, + }, + }; + + return i2c_transfer(tj9->client->adapter, msgs, 2); +} + +static void kxtj9_report_acceleration_data(struct kxtj9_data *tj9) +{ + s16 acc_data[3]; /* Data bytes from hardware xL, xH, yL, yH, zL, zH */ + s16 x, y, z; + int err; + + err = kxtj9_i2c_read(tj9, XOUT_L, (u8 *)acc_data, 6); + if (err < 0) + dev_err(&tj9->client->dev, "accelerometer data read failed\n"); + + x = le16_to_cpu(acc_data[tj9->pdata.axis_map_x]); + y = le16_to_cpu(acc_data[tj9->pdata.axis_map_y]); + z = le16_to_cpu(acc_data[tj9->pdata.axis_map_z]); + + x >>= tj9->shift; + y >>= tj9->shift; + z >>= tj9->shift; + + input_report_abs(tj9->input_dev, ABS_X, tj9->pdata.negate_x ? -x : x); + input_report_abs(tj9->input_dev, ABS_Y, tj9->pdata.negate_y ? -y : y); + input_report_abs(tj9->input_dev, ABS_Z, tj9->pdata.negate_z ? -z : z); + input_sync(tj9->input_dev); +} + +static irqreturn_t kxtj9_isr(int irq, void *dev) +{ + struct kxtj9_data *tj9 = dev; + int err; + + /* data ready is the only possible interrupt type */ + kxtj9_report_acceleration_data(tj9); + + err = i2c_smbus_read_byte_data(tj9->client, INT_REL); + if (err < 0) + dev_err(&tj9->client->dev, + "error clearing interrupt status: %d\n", err); + + return IRQ_HANDLED; +} + +static int kxtj9_update_g_range(struct kxtj9_data *tj9, u8 new_g_range) +{ + switch (new_g_range) { + case KXTJ9_G_2G: + tj9->shift = 4; + break; + case KXTJ9_G_4G: + tj9->shift = 3; + break; + case KXTJ9_G_8G: + tj9->shift = 2; + break; + default: + return -EINVAL; + } + + tj9->ctrl_reg1 &= 0xe7; + tj9->ctrl_reg1 |= new_g_range; + + return 0; +} + +static int kxtj9_update_odr(struct kxtj9_data *tj9, unsigned int poll_interval) +{ + int err; + int i; + + /* Use the lowest ODR that can support the requested poll interval */ + for (i = 0; i < ARRAY_SIZE(kxtj9_odr_table); i++) { + tj9->data_ctrl = kxtj9_odr_table[i].mask; + if (poll_interval < kxtj9_odr_table[i].cutoff) + break; + } + + err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, 0); + if (err < 0) + return err; + + err = i2c_smbus_write_byte_data(tj9->client, DATA_CTRL, tj9->data_ctrl); + if (err < 0) + return err; + + err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, tj9->ctrl_reg1); + if (err < 0) + return err; + + return 0; +} + +static int kxtj9_device_power_on(struct kxtj9_data *tj9) +{ + if (tj9->pdata.power_on) + return tj9->pdata.power_on(); + + return 0; +} + +static void kxtj9_device_power_off(struct kxtj9_data *tj9) +{ + int err; + + tj9->ctrl_reg1 &= PC1_OFF; + err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, tj9->ctrl_reg1); + if (err < 0) + dev_err(&tj9->client->dev, "soft power off failed\n"); + + if (tj9->pdata.power_off) + tj9->pdata.power_off(); +} + +static int kxtj9_enable(struct kxtj9_data *tj9) +{ + int err; + + err = kxtj9_device_power_on(tj9); + if (err < 0) + return err; + + /* ensure that PC1 is cleared before updating control registers */ + err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, 0); + if (err < 0) + return err; + + /* only write INT_CTRL_REG1 if in irq mode */ + if (tj9->client->irq) { + err = i2c_smbus_write_byte_data(tj9->client, + INT_CTRL1, tj9->int_ctrl); + if (err < 0) + return err; + } + + err = kxtj9_update_g_range(tj9, tj9->pdata.g_range); + if (err < 0) + return err; + + /* turn on outputs */ + tj9->ctrl_reg1 |= PC1_ON; + err = i2c_smbus_write_byte_data(tj9->client, CTRL_REG1, tj9->ctrl_reg1); + if (err < 0) + return err; + + err = kxtj9_update_odr(tj9, tj9->last_poll_interval); + if (err < 0) + return err; + + /* clear initial interrupt if in irq mode */ + if (tj9->client->irq) { + err = i2c_smbus_read_byte_data(tj9->client, INT_REL); + if (err < 0) { + dev_err(&tj9->client->dev, + "error clearing interrupt: %d\n", err); + goto fail; + } + } + + return 0; + +fail: + kxtj9_device_power_off(tj9); + return err; +} + +static void kxtj9_disable(struct kxtj9_data *tj9) +{ + kxtj9_device_power_off(tj9); +} + +static int kxtj9_input_open(struct input_dev *input) +{ + struct kxtj9_data *tj9 = input_get_drvdata(input); + + return kxtj9_enable(tj9); +} + +static void kxtj9_input_close(struct input_dev *dev) +{ + struct kxtj9_data *tj9 = input_get_drvdata(dev); + + kxtj9_disable(tj9); +} + +/* + * When IRQ mode is selected, we need to provide an interface to allow the user + * to change the output data rate of the part. For consistency, we are using + * the set_poll method, which accepts a poll interval in milliseconds, and then + * calls update_odr() while passing this value as an argument. In IRQ mode, the + * data outputs will not be read AT the requested poll interval, rather, the + * lowest ODR that can support the requested interval. The client application + * will be responsible for retrieving data from the input node at the desired + * interval. + */ + +/* Returns currently selected poll interval (in ms) */ +static ssize_t kxtj9_get_poll(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct i2c_client *client = to_i2c_client(dev); + struct kxtj9_data *tj9 = i2c_get_clientdata(client); + + return sprintf(buf, "%d\n", tj9->last_poll_interval); +} + +/* Allow users to select a new poll interval (in ms) */ +static ssize_t kxtj9_set_poll(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct i2c_client *client = to_i2c_client(dev); + struct kxtj9_data *tj9 = i2c_get_clientdata(client); + struct input_dev *input_dev = tj9->input_dev; + unsigned int interval; + int error; + + error = kstrtouint(buf, 10, &interval); + if (error < 0) + return error; + + /* Lock the device to prevent races with open/close (and itself) */ + mutex_lock(&input_dev->mutex); + + disable_irq(client->irq); + + /* + * Set current interval to the greater of the minimum interval or + * the requested interval + */ + tj9->last_poll_interval = max(interval, tj9->pdata.min_interval); + + kxtj9_update_odr(tj9, tj9->last_poll_interval); + + enable_irq(client->irq); + mutex_unlock(&input_dev->mutex); + + return count; +} + +static DEVICE_ATTR(poll, S_IRUGO|S_IWUSR, kxtj9_get_poll, kxtj9_set_poll); + +static struct attribute *kxtj9_attributes[] = { + &dev_attr_poll.attr, + NULL +}; + +static struct attribute_group kxtj9_attribute_group = { + .attrs = kxtj9_attributes +}; + +static void kxtj9_poll(struct input_dev *input) +{ + struct kxtj9_data *tj9 = input_get_drvdata(input); + unsigned int poll_interval = input_get_poll_interval(input); + + kxtj9_report_acceleration_data(tj9); + + if (poll_interval != tj9->last_poll_interval) { + kxtj9_update_odr(tj9, poll_interval); + tj9->last_poll_interval = poll_interval; + } +} + +static void kxtj9_platform_exit(void *data) +{ + struct kxtj9_data *tj9 = data; + + if (tj9->pdata.exit) + tj9->pdata.exit(); +} + +static int kxtj9_verify(struct kxtj9_data *tj9) +{ + int retval; + + retval = kxtj9_device_power_on(tj9); + if (retval < 0) + return retval; + + retval = i2c_smbus_read_byte_data(tj9->client, WHO_AM_I); + if (retval < 0) { + dev_err(&tj9->client->dev, "read err int source\n"); + goto out; + } + + retval = (retval != 0x07 && retval != 0x08) ? -EIO : 0; + +out: + kxtj9_device_power_off(tj9); + return retval; +} + +static int kxtj9_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + const struct kxtj9_platform_data *pdata = + dev_get_platdata(&client->dev); + struct kxtj9_data *tj9; + struct input_dev *input_dev; + int err; + + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE_DATA)) { + dev_err(&client->dev, "client is not i2c capable\n"); + return -ENXIO; + } + + if (!pdata) { + dev_err(&client->dev, "platform data is NULL; exiting\n"); + return -EINVAL; + } + + tj9 = devm_kzalloc(&client->dev, sizeof(*tj9), GFP_KERNEL); + if (!tj9) { + dev_err(&client->dev, + "failed to allocate memory for module data\n"); + return -ENOMEM; + } + + tj9->client = client; + tj9->pdata = *pdata; + + if (pdata->init) { + err = pdata->init(); + if (err < 0) + return err; + } + + err = devm_add_action_or_reset(&client->dev, kxtj9_platform_exit, tj9); + if (err) + return err; + + err = kxtj9_verify(tj9); + if (err < 0) { + dev_err(&client->dev, "device not recognized\n"); + return err; + } + + i2c_set_clientdata(client, tj9); + + tj9->ctrl_reg1 = tj9->pdata.res_12bit | tj9->pdata.g_range; + tj9->last_poll_interval = tj9->pdata.init_interval; + + input_dev = devm_input_allocate_device(&client->dev); + if (!input_dev) { + dev_err(&client->dev, "input device allocate failed\n"); + return -ENOMEM; + } + + input_set_drvdata(input_dev, tj9); + tj9->input_dev = input_dev; + + input_dev->name = "kxtj9_accel"; + input_dev->id.bustype = BUS_I2C; + + input_dev->open = kxtj9_input_open; + input_dev->close = kxtj9_input_close; + + input_set_abs_params(input_dev, ABS_X, -G_MAX, G_MAX, FUZZ, FLAT); + input_set_abs_params(input_dev, ABS_Y, -G_MAX, G_MAX, FUZZ, FLAT); + input_set_abs_params(input_dev, ABS_Z, -G_MAX, G_MAX, FUZZ, FLAT); + + if (client->irq <= 0) { + err = input_setup_polling(input_dev, kxtj9_poll); + if (err) + return err; + } + + err = input_register_device(input_dev); + if (err) { + dev_err(&client->dev, + "unable to register input polled device %s: %d\n", + input_dev->name, err); + return err; + } + + if (client->irq) { + /* If in irq mode, populate INT_CTRL_REG1 and enable DRDY. */ + tj9->int_ctrl |= KXTJ9_IEN | KXTJ9_IEA | KXTJ9_IEL; + tj9->ctrl_reg1 |= DRDYE; + + err = devm_request_threaded_irq(&client->dev, client->irq, + NULL, kxtj9_isr, + IRQF_TRIGGER_RISING | + IRQF_ONESHOT, + "kxtj9-irq", tj9); + if (err) { + dev_err(&client->dev, "request irq failed: %d\n", err); + return err; + } + + err = devm_device_add_group(&client->dev, + &kxtj9_attribute_group); + if (err) { + dev_err(&client->dev, "sysfs create failed: %d\n", err); + return err; + } + } + + return 0; +} + +static int __maybe_unused kxtj9_suspend(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct kxtj9_data *tj9 = i2c_get_clientdata(client); + struct input_dev *input_dev = tj9->input_dev; + + mutex_lock(&input_dev->mutex); + + if (input_dev->users) + kxtj9_disable(tj9); + + mutex_unlock(&input_dev->mutex); + return 0; +} + +static int __maybe_unused kxtj9_resume(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct kxtj9_data *tj9 = i2c_get_clientdata(client); + struct input_dev *input_dev = tj9->input_dev; + + mutex_lock(&input_dev->mutex); + + if (input_dev->users) + kxtj9_enable(tj9); + + mutex_unlock(&input_dev->mutex); + return 0; +} + +static SIMPLE_DEV_PM_OPS(kxtj9_pm_ops, kxtj9_suspend, kxtj9_resume); + +static const struct i2c_device_id kxtj9_id[] = { + { NAME, 0 }, + { }, +}; + +MODULE_DEVICE_TABLE(i2c, kxtj9_id); + +static struct i2c_driver kxtj9_driver = { + .driver = { + .name = NAME, + .pm = &kxtj9_pm_ops, + }, + .probe = kxtj9_probe, + .id_table = kxtj9_id, +}; + +module_i2c_driver(kxtj9_driver); + +MODULE_DESCRIPTION("KXTJ9 accelerometer driver"); +MODULE_AUTHOR("Chris Hudson <chudson@kionix.com>"); +MODULE_LICENSE("GPL"); |